Andrew's git / gitweb.git / daemon.c
?
daemon.con commit Merge branch 'bw/rebase-autostash-keep-current-branch' (974bdb0)
   1#include "cache.h"
   2#include "config.h"
   3#include "pkt-line.h"
   4#include "run-command.h"
   5#include "strbuf.h"
   6#include "string-list.h"
   7
   8#ifdef NO_INITGROUPS
   9#define initgroups(x, y) (0) /* nothing */
  10#endif
  11
  12static enum log_destination {
  13        LOG_DESTINATION_UNSET = -1,
  14        LOG_DESTINATION_NONE = 0,
  15        LOG_DESTINATION_STDERR = 1,
  16        LOG_DESTINATION_SYSLOG = 2,
  17} log_destination = LOG_DESTINATION_UNSET;
  18static int verbose;
  19static int reuseaddr;
  20static int informative_errors;
  21
  22static const char daemon_usage[] =
  23"git daemon [--verbose] [--syslog] [--export-all]\n"
  24"           [--timeout=<n>] [--init-timeout=<n>] [--max-connections=<n>]\n"
  25"           [--strict-paths] [--base-path=<path>] [--base-path-relaxed]\n"
  26"           [--user-path | --user-path=<path>]\n"
  27"           [--interpolated-path=<path>]\n"
  28"           [--reuseaddr] [--pid-file=<file>]\n"
  29"           [--(enable|disable|allow-override|forbid-override)=<service>]\n"
  30"           [--access-hook=<path>]\n"
  31"           [--inetd | [--listen=<host_or_ipaddr>] [--port=<n>]\n"
  32"                      [--detach] [--user=<user> [--group=<group>]]\n"
  33"           [--log-destination=(stderr|syslog|none)]\n"
  34"           [<directory>...]";
  35
  36/* List of acceptable pathname prefixes */
  37static const char **ok_paths;
  38static int strict_paths;
  39
  40/* If this is set, git-daemon-export-ok is not required */
  41static int export_all_trees;
  42
  43/* Take all paths relative to this one if non-NULL */
  44static const char *base_path;
  45static const char *interpolated_path;
  46static int base_path_relaxed;
  47
  48/* If defined, ~user notation is allowed and the string is inserted
  49 * after ~user/.  E.g. a request to git://host/~alice/frotz would
  50 * go to /home/alice/pub_git/frotz with --user-path=pub_git.
  51 */
  52static const char *user_path;
  53
  54/* Timeout, and initial timeout */
  55static unsigned int timeout;
  56static unsigned int init_timeout;
  57
  58struct hostinfo {
  59        struct strbuf hostname;
  60        struct strbuf canon_hostname;
  61        struct strbuf ip_address;
  62        struct strbuf tcp_port;
  63        unsigned int hostname_lookup_done:1;
  64        unsigned int saw_extended_args:1;
  65};
  66
  67static void lookup_hostname(struct hostinfo *hi);
  68
  69static const char *get_canon_hostname(struct hostinfo *hi)
  70{
  71        lookup_hostname(hi);
  72        return hi->canon_hostname.buf;
  73}
  74
  75static const char *get_ip_address(struct hostinfo *hi)
  76{
  77        lookup_hostname(hi);
  78        return hi->ip_address.buf;
  79}
  80
  81static void logreport(int priority, const char *err, va_list params)
  82{
  83        switch (log_destination) {
  84        case LOG_DESTINATION_SYSLOG: {
  85                char buf[1024];
  86                vsnprintf(buf, sizeof(buf), err, params);
  87                syslog(priority, "%s", buf);
  88                break;
  89        }
  90        case LOG_DESTINATION_STDERR:
  91                /*
  92                 * Since stderr is set to buffered mode, the
  93                 * logging of different processes will not overlap
  94                 * unless they overflow the (rather big) buffers.
  95                 */
  96                fprintf(stderr, "[%"PRIuMAX"] ", (uintmax_t)getpid());
  97                vfprintf(stderr, err, params);
  98                fputc('\n', stderr);
  99                fflush(stderr);
 100                break;
 101        case LOG_DESTINATION_NONE:
 102                break;
 103        case LOG_DESTINATION_UNSET:
 104                BUG("log destination not initialized correctly");
 105        }
 106}
 107
 108__attribute__((format (printf, 1, 2)))
 109static void logerror(const char *err, ...)
 110{
 111        va_list params;
 112        va_start(params, err);
 113        logreport(LOG_ERR, err, params);
 114        va_end(params);
 115}
 116
 117__attribute__((format (printf, 1, 2)))
 118static void loginfo(const char *err, ...)
 119{
 120        va_list params;
 121        if (!verbose)
 122                return;
 123        va_start(params, err);
 124        logreport(LOG_INFO, err, params);
 125        va_end(params);
 126}
 127
 128static void NORETURN daemon_die(const char *err, va_list params)
 129{
 130        logreport(LOG_ERR, err, params);
 131        exit(1);
 132}
 133
 134struct expand_path_context {
 135        const char *directory;
 136        struct hostinfo *hostinfo;
 137};
 138
 139static size_t expand_path(struct strbuf *sb, const char *placeholder, void *ctx)
 140{
 141        struct expand_path_context *context = ctx;
 142        struct hostinfo *hi = context->hostinfo;
 143
 144        switch (placeholder[0]) {
 145        case 'H':
 146                strbuf_addbuf(sb, &hi->hostname);
 147                return 1;
 148        case 'C':
 149                if (placeholder[1] == 'H') {
 150                        strbuf_addstr(sb, get_canon_hostname(hi));
 151                        return 2;
 152                }
 153                break;
 154        case 'I':
 155                if (placeholder[1] == 'P') {
 156                        strbuf_addstr(sb, get_ip_address(hi));
 157                        return 2;
 158                }
 159                break;
 160        case 'P':
 161                strbuf_addbuf(sb, &hi->tcp_port);
 162                return 1;
 163        case 'D':
 164                strbuf_addstr(sb, context->directory);
 165                return 1;
 166        }
 167        return 0;
 168}
 169
 170static const char *path_ok(const char *directory, struct hostinfo *hi)
 171{
 172        static char rpath[PATH_MAX];
 173        static char interp_path[PATH_MAX];
 174        size_t rlen;
 175        const char *path;
 176        const char *dir;
 177
 178        dir = directory;
 179
 180        if (daemon_avoid_alias(dir)) {
 181                logerror("'%s': aliased", dir);
 182                return NULL;
 183        }
 184
 185        if (*dir == '~') {
 186                if (!user_path) {
 187                        logerror("'%s': User-path not allowed", dir);
 188                        return NULL;
 189                }
 190                if (*user_path) {
 191                        /* Got either "~alice" or "~alice/foo";
 192                         * rewrite them to "~alice/%s" or
 193                         * "~alice/%s/foo".
 194                         */
 195                        int namlen, restlen = strlen(dir);
 196                        const char *slash = strchr(dir, '/');
 197                        if (!slash)
 198                                slash = dir + restlen;
 199                        namlen = slash - dir;
 200                        restlen -= namlen;
 201                        loginfo("userpath <%s>, request <%s>, namlen %d, restlen %d, slash <%s>", user_path, dir, namlen, restlen, slash);
 202                        rlen = snprintf(rpath, sizeof(rpath), "%.*s/%s%.*s",
 203                                        namlen, dir, user_path, restlen, slash);
 204                        if (rlen >= sizeof(rpath)) {
 205                                logerror("user-path too large: %s", rpath);
 206                                return NULL;
 207                        }
 208                        dir = rpath;
 209                }
 210        }
 211        else if (interpolated_path && hi->saw_extended_args) {
 212                struct strbuf expanded_path = STRBUF_INIT;
 213                struct expand_path_context context;
 214
 215                context.directory = directory;
 216                context.hostinfo = hi;
 217
 218                if (*dir != '/') {
 219                        /* Allow only absolute */
 220                        logerror("'%s': Non-absolute path denied (interpolated-path active)", dir);
 221                        return NULL;
 222                }
 223
 224                strbuf_expand(&expanded_path, interpolated_path,
 225                              expand_path, &context);
 226
 227                rlen = strlcpy(interp_path, expanded_path.buf,
 228                               sizeof(interp_path));
 229                if (rlen >= sizeof(interp_path)) {
 230                        logerror("interpolated path too large: %s",
 231                                 interp_path);
 232                        return NULL;
 233                }
 234
 235                strbuf_release(&expanded_path);
 236                loginfo("Interpolated dir '%s'", interp_path);
 237
 238                dir = interp_path;
 239        }
 240        else if (base_path) {
 241                if (*dir != '/') {
 242                        /* Allow only absolute */
 243                        logerror("'%s': Non-absolute path denied (base-path active)", dir);
 244                        return NULL;
 245                }
 246                rlen = snprintf(rpath, sizeof(rpath), "%s%s", base_path, dir);
 247                if (rlen >= sizeof(rpath)) {
 248                        logerror("base-path too large: %s", rpath);
 249                        return NULL;
 250                }
 251                dir = rpath;
 252        }
 253
 254        path = enter_repo(dir, strict_paths);
 255        if (!path && base_path && base_path_relaxed) {
 256                /*
 257                 * if we fail and base_path_relaxed is enabled, try without
 258                 * prefixing the base path
 259                 */
 260                dir = directory;
 261                path = enter_repo(dir, strict_paths);
 262        }
 263
 264        if (!path) {
 265                logerror("'%s' does not appear to be a git repository", dir);
 266                return NULL;
 267        }
 268
 269        if ( ok_paths && *ok_paths ) {
 270                const char **pp;
 271                int pathlen = strlen(path);
 272
 273                /* The validation is done on the paths after enter_repo
 274                 * appends optional {.git,.git/.git} and friends, but
 275                 * it does not use getcwd().  So if your /pub is
 276                 * a symlink to /mnt/pub, you can whitelist /pub and
 277                 * do not have to say /mnt/pub.
 278                 * Do not say /pub/.
 279                 */
 280                for ( pp = ok_paths ; *pp ; pp++ ) {
 281                        int len = strlen(*pp);
 282                        if (len <= pathlen &&
 283                            !memcmp(*pp, path, len) &&
 284                            (path[len] == '\0' ||
 285                             (!strict_paths && path[len] == '/')))
 286                                return path;
 287                }
 288        }
 289        else {
 290                /* be backwards compatible */
 291                if (!strict_paths)
 292                        return path;
 293        }
 294
 295        logerror("'%s': not in whitelist", path);
 296        return NULL;            /* Fallthrough. Deny by default */
 297}
 298
 299typedef int (*daemon_service_fn)(const struct argv_array *env);
 300struct daemon_service {
 301        const char *name;
 302        const char *config_name;
 303        daemon_service_fn fn;
 304        int enabled;
 305        int overridable;
 306};
 307
 308static int daemon_error(const char *dir, const char *msg)
 309{
 310        if (!informative_errors)
 311                msg = "access denied or repository not exported";
 312        packet_write_fmt(1, "ERR %s: %s", msg, dir);
 313        return -1;
 314}
 315
 316static const char *access_hook;
 317
 318static int run_access_hook(struct daemon_service *service, const char *dir,
 319                           const char *path, struct hostinfo *hi)
 320{
 321        struct child_process child = CHILD_PROCESS_INIT;
 322        struct strbuf buf = STRBUF_INIT;
 323        const char *argv[8];
 324        const char **arg = argv;
 325        char *eol;
 326        int seen_errors = 0;
 327
 328        *arg++ = access_hook;
 329        *arg++ = service->name;
 330        *arg++ = path;
 331        *arg++ = hi->hostname.buf;
 332        *arg++ = get_canon_hostname(hi);
 333        *arg++ = get_ip_address(hi);
 334        *arg++ = hi->tcp_port.buf;
 335        *arg = NULL;
 336
 337        child.use_shell = 1;
 338        child.argv = argv;
 339        child.no_stdin = 1;
 340        child.no_stderr = 1;
 341        child.out = -1;
 342        if (start_command(&child)) {
 343                logerror("daemon access hook '%s' failed to start",
 344                         access_hook);
 345                goto error_return;
 346        }
 347        if (strbuf_read(&buf, child.out, 0) < 0) {
 348                logerror("failed to read from pipe to daemon access hook '%s'",
 349                         access_hook);
 350                strbuf_reset(&buf);
 351                seen_errors = 1;
 352        }
 353        if (close(child.out) < 0) {
 354                logerror("failed to close pipe to daemon access hook '%s'",
 355                         access_hook);
 356                seen_errors = 1;
 357        }
 358        if (finish_command(&child))
 359                seen_errors = 1;
 360
 361        if (!seen_errors) {
 362                strbuf_release(&buf);
 363                return 0;
 364        }
 365
 366error_return:
 367        strbuf_ltrim(&buf);
 368        if (!buf.len)
 369                strbuf_addstr(&buf, "service rejected");
 370        eol = strchr(buf.buf, '\n');
 371        if (eol)
 372                *eol = '\0';
 373        errno = EACCES;
 374        daemon_error(dir, buf.buf);
 375        strbuf_release(&buf);
 376        return -1;
 377}
 378
 379static int run_service(const char *dir, struct daemon_service *service,
 380                       struct hostinfo *hi, const struct argv_array *env)
 381{
 382        const char *path;
 383        int enabled = service->enabled;
 384        struct strbuf var = STRBUF_INIT;
 385
 386        loginfo("Request %s for '%s'", service->name, dir);
 387
 388        if (!enabled && !service->overridable) {
 389                logerror("'%s': service not enabled.", service->name);
 390                errno = EACCES;
 391                return daemon_error(dir, "service not enabled");
 392        }
 393
 394        if (!(path = path_ok(dir, hi)))
 395                return daemon_error(dir, "no such repository");
 396
 397        /*
 398         * Security on the cheap.
 399         *
 400         * We want a readable HEAD, usable "objects" directory, and
 401         * a "git-daemon-export-ok" flag that says that the other side
 402         * is ok with us doing this.
 403         *
 404         * path_ok() uses enter_repo() and does whitelist checking.
 405         * We only need to make sure the repository is exported.
 406         */
 407
 408        if (!export_all_trees && access("git-daemon-export-ok", F_OK)) {
 409                logerror("'%s': repository not exported.", path);
 410                errno = EACCES;
 411                return daemon_error(dir, "repository not exported");
 412        }
 413
 414        if (service->overridable) {
 415                strbuf_addf(&var, "daemon.%s", service->config_name);
 416                git_config_get_bool(var.buf, &enabled);
 417                strbuf_release(&var);
 418        }
 419        if (!enabled) {
 420                logerror("'%s': service not enabled for '%s'",
 421                         service->name, path);
 422                errno = EACCES;
 423                return daemon_error(dir, "service not enabled");
 424        }
 425
 426        /*
 427         * Optionally, a hook can choose to deny access to the
 428         * repository depending on the phase of the moon.
 429         */
 430        if (access_hook && run_access_hook(service, dir, path, hi))
 431                return -1;
 432
 433        /*
 434         * We'll ignore SIGTERM from now on, we have a
 435         * good client.
 436         */
 437        signal(SIGTERM, SIG_IGN);
 438
 439        return service->fn(env);
 440}
 441
 442static void copy_to_log(int fd)
 443{
 444        struct strbuf line = STRBUF_INIT;
 445        FILE *fp;
 446
 447        fp = fdopen(fd, "r");
 448        if (fp == NULL) {
 449                logerror("fdopen of error channel failed");
 450                close(fd);
 451                return;
 452        }
 453
 454        while (strbuf_getline_lf(&line, fp) != EOF) {
 455                logerror("%s", line.buf);
 456                strbuf_setlen(&line, 0);
 457        }
 458
 459        strbuf_release(&line);
 460        fclose(fp);
 461}
 462
 463static int run_service_command(struct child_process *cld)
 464{
 465        argv_array_push(&cld->args, ".");
 466        cld->git_cmd = 1;
 467        cld->err = -1;
 468        if (start_command(cld))
 469                return -1;
 470
 471        close(0);
 472        close(1);
 473
 474        copy_to_log(cld->err);
 475
 476        return finish_command(cld);
 477}
 478
 479static int upload_pack(const struct argv_array *env)
 480{
 481        struct child_process cld = CHILD_PROCESS_INIT;
 482        argv_array_pushl(&cld.args, "upload-pack", "--strict", NULL);
 483        argv_array_pushf(&cld.args, "--timeout=%u", timeout);
 484
 485        argv_array_pushv(&cld.env_array, env->argv);
 486
 487        return run_service_command(&cld);
 488}
 489
 490static int upload_archive(const struct argv_array *env)
 491{
 492        struct child_process cld = CHILD_PROCESS_INIT;
 493        argv_array_push(&cld.args, "upload-archive");
 494
 495        argv_array_pushv(&cld.env_array, env->argv);
 496
 497        return run_service_command(&cld);
 498}
 499
 500static int receive_pack(const struct argv_array *env)
 501{
 502        struct child_process cld = CHILD_PROCESS_INIT;
 503        argv_array_push(&cld.args, "receive-pack");
 504
 505        argv_array_pushv(&cld.env_array, env->argv);
 506
 507        return run_service_command(&cld);
 508}
 509
 510static struct daemon_service daemon_service[] = {
 511        { "upload-archive", "uploadarch", upload_archive, 0, 1 },
 512        { "upload-pack", "uploadpack", upload_pack, 1, 1 },
 513        { "receive-pack", "receivepack", receive_pack, 0, 1 },
 514};
 515
 516static void enable_service(const char *name, int ena)
 517{
 518        int i;
 519        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 520                if (!strcmp(daemon_service[i].name, name)) {
 521                        daemon_service[i].enabled = ena;
 522                        return;
 523                }
 524        }
 525        die("No such service %s", name);
 526}
 527
 528static void make_service_overridable(const char *name, int ena)
 529{
 530        int i;
 531        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 532                if (!strcmp(daemon_service[i].name, name)) {
 533                        daemon_service[i].overridable = ena;
 534                        return;
 535                }
 536        }
 537        die("No such service %s", name);
 538}
 539
 540static void parse_host_and_port(char *hostport, char **host,
 541        char **port)
 542{
 543        if (*hostport == '[') {
 544                char *end;
 545
 546                end = strchr(hostport, ']');
 547                if (!end)
 548                        die("Invalid request ('[' without ']')");
 549                *end = '\0';
 550                *host = hostport + 1;
 551                if (!end[1])
 552                        *port = NULL;
 553                else if (end[1] == ':')
 554                        *port = end + 2;
 555                else
 556                        die("Garbage after end of host part");
 557        } else {
 558                *host = hostport;
 559                *port = strrchr(hostport, ':');
 560                if (*port) {
 561                        **port = '\0';
 562                        ++*port;
 563                }
 564        }
 565}
 566
 567/*
 568 * Sanitize a string from the client so that it's OK to be inserted into a
 569 * filesystem path. Specifically, we disallow slashes, runs of "..", and
 570 * trailing and leading dots, which means that the client cannot escape
 571 * our base path via ".." traversal.
 572 */
 573static void sanitize_client(struct strbuf *out, const char *in)
 574{
 575        for (; *in; in++) {
 576                if (*in == '/')
 577                        continue;
 578                if (*in == '.' && (!out->len || out->buf[out->len - 1] == '.'))
 579                        continue;
 580                strbuf_addch(out, *in);
 581        }
 582
 583        while (out->len && out->buf[out->len - 1] == '.')
 584                strbuf_setlen(out, out->len - 1);
 585}
 586
 587/*
 588 * Like sanitize_client, but we also perform any canonicalization
 589 * to make life easier on the admin.
 590 */
 591static void canonicalize_client(struct strbuf *out, const char *in)
 592{
 593        sanitize_client(out, in);
 594        strbuf_tolower(out);
 595}
 596
 597/*
 598 * Read the host as supplied by the client connection.
 599 *
 600 * Returns a pointer to the character after the NUL byte terminating the host
 601 * arguemnt, or 'extra_args' if there is no host arguemnt.
 602 */
 603static char *parse_host_arg(struct hostinfo *hi, char *extra_args, int buflen)
 604{
 605        char *val;
 606        int vallen;
 607        char *end = extra_args + buflen;
 608
 609        if (extra_args < end && *extra_args) {
 610                hi->saw_extended_args = 1;
 611                if (strncasecmp("host=", extra_args, 5) == 0) {
 612                        val = extra_args + 5;
 613                        vallen = strlen(val) + 1;
 614                        loginfo("Extended attribute \"host\": %s", val);
 615                        if (*val) {
 616                                /* Split <host>:<port> at colon. */
 617                                char *host;
 618                                char *port;
 619                                parse_host_and_port(val, &host, &port);
 620                                if (port)
 621                                        sanitize_client(&hi->tcp_port, port);
 622                                canonicalize_client(&hi->hostname, host);
 623                                hi->hostname_lookup_done = 0;
 624                        }
 625
 626                        /* On to the next one */
 627                        extra_args = val + vallen;
 628                }
 629                if (extra_args < end && *extra_args)
 630                        die("Invalid request");
 631        }
 632
 633        return extra_args;
 634}
 635
 636static void parse_extra_args(struct hostinfo *hi, struct argv_array *env,
 637                             char *extra_args, int buflen)
 638{
 639        const char *end = extra_args + buflen;
 640        struct strbuf git_protocol = STRBUF_INIT;
 641
 642        /* First look for the host argument */
 643        extra_args = parse_host_arg(hi, extra_args, buflen);
 644
 645        /* Look for additional arguments places after a second NUL byte */
 646        for (; extra_args < end; extra_args += strlen(extra_args) + 1) {
 647                const char *arg = extra_args;
 648
 649                /*
 650                 * Parse the extra arguments, adding most to 'git_protocol'
 651                 * which will be used to set the 'GIT_PROTOCOL' envvar in the
 652                 * service that will be run.
 653                 *
 654                 * If there ends up being a particular arg in the future that
 655                 * git-daemon needs to parse specificly (like the 'host' arg)
 656                 * then it can be parsed here and not added to 'git_protocol'.
 657                 */
 658                if (*arg) {
 659                        if (git_protocol.len > 0)
 660                                strbuf_addch(&git_protocol, ':');
 661                        strbuf_addstr(&git_protocol, arg);
 662                }
 663        }
 664
 665        if (git_protocol.len > 0) {
 666                loginfo("Extended attribute \"protocol\": %s", git_protocol.buf);
 667                argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=%s",
 668                                 git_protocol.buf);
 669        }
 670        strbuf_release(&git_protocol);
 671}
 672
 673/*
 674 * Locate canonical hostname and its IP address.
 675 */
 676static void lookup_hostname(struct hostinfo *hi)
 677{
 678        if (!hi->hostname_lookup_done && hi->hostname.len) {
 679#ifndef NO_IPV6
 680                struct addrinfo hints;
 681                struct addrinfo *ai;
 682                int gai;
 683                static char addrbuf[HOST_NAME_MAX + 1];
 684
 685                memset(&hints, 0, sizeof(hints));
 686                hints.ai_flags = AI_CANONNAME;
 687
 688                gai = getaddrinfo(hi->hostname.buf, NULL, &hints, &ai);
 689                if (!gai) {
 690                        struct sockaddr_in *sin_addr = (void *)ai->ai_addr;
 691
 692                        inet_ntop(AF_INET, &sin_addr->sin_addr,
 693                                  addrbuf, sizeof(addrbuf));
 694                        strbuf_addstr(&hi->ip_address, addrbuf);
 695
 696                        if (ai->ai_canonname)
 697                                sanitize_client(&hi->canon_hostname,
 698                                                ai->ai_canonname);
 699                        else
 700                                strbuf_addbuf(&hi->canon_hostname,
 701                                              &hi->ip_address);
 702
 703                        freeaddrinfo(ai);
 704                }
 705#else
 706                struct hostent *hent;
 707                struct sockaddr_in sa;
 708                char **ap;
 709                static char addrbuf[HOST_NAME_MAX + 1];
 710
 711                hent = gethostbyname(hi->hostname.buf);
 712                if (hent) {
 713                        ap = hent->h_addr_list;
 714                        memset(&sa, 0, sizeof sa);
 715                        sa.sin_family = hent->h_addrtype;
 716                        sa.sin_port = htons(0);
 717                        memcpy(&sa.sin_addr, *ap, hent->h_length);
 718
 719                        inet_ntop(hent->h_addrtype, &sa.sin_addr,
 720                                  addrbuf, sizeof(addrbuf));
 721
 722                        sanitize_client(&hi->canon_hostname, hent->h_name);
 723                        strbuf_addstr(&hi->ip_address, addrbuf);
 724                }
 725#endif
 726                hi->hostname_lookup_done = 1;
 727        }
 728}
 729
 730static void hostinfo_init(struct hostinfo *hi)
 731{
 732        memset(hi, 0, sizeof(*hi));
 733        strbuf_init(&hi->hostname, 0);
 734        strbuf_init(&hi->canon_hostname, 0);
 735        strbuf_init(&hi->ip_address, 0);
 736        strbuf_init(&hi->tcp_port, 0);
 737}
 738
 739static void hostinfo_clear(struct hostinfo *hi)
 740{
 741        strbuf_release(&hi->hostname);
 742        strbuf_release(&hi->canon_hostname);
 743        strbuf_release(&hi->ip_address);
 744        strbuf_release(&hi->tcp_port);
 745}
 746
 747static void set_keep_alive(int sockfd)
 748{
 749        int ka = 1;
 750
 751        if (setsockopt(sockfd, SOL_SOCKET, SO_KEEPALIVE, &ka, sizeof(ka)) < 0) {
 752                if (errno != ENOTSOCK)
 753                        logerror("unable to set SO_KEEPALIVE on socket: %s",
 754                                strerror(errno));
 755        }
 756}
 757
 758static int execute(void)
 759{
 760        char *line = packet_buffer;
 761        int pktlen, len, i;
 762        char *addr = getenv("REMOTE_ADDR"), *port = getenv("REMOTE_PORT");
 763        struct hostinfo hi;
 764        struct argv_array env = ARGV_ARRAY_INIT;
 765
 766        hostinfo_init(&hi);
 767
 768        if (addr)
 769                loginfo("Connection from %s:%s", addr, port);
 770
 771        set_keep_alive(0);
 772        alarm(init_timeout ? init_timeout : timeout);
 773        pktlen = packet_read(0, NULL, NULL, packet_buffer, sizeof(packet_buffer), 0);
 774        alarm(0);
 775
 776        len = strlen(line);
 777        if (len && line[len-1] == '\n')
 778                line[len-1] = 0;
 779
 780        /* parse additional args hidden behind a NUL byte */
 781        if (len != pktlen)
 782                parse_extra_args(&hi, &env, line + len + 1, pktlen - len - 1);
 783
 784        for (i = 0; i < ARRAY_SIZE(daemon_service); i++) {
 785                struct daemon_service *s = &(daemon_service[i]);
 786                const char *arg;
 787
 788                if (skip_prefix(line, "git-", &arg) &&
 789                    skip_prefix(arg, s->name, &arg) &&
 790                    *arg++ == ' ') {
 791                        /*
 792                         * Note: The directory here is probably context sensitive,
 793                         * and might depend on the actual service being performed.
 794                         */
 795                        int rc = run_service(arg, s, &hi, &env);
 796                        hostinfo_clear(&hi);
 797                        argv_array_clear(&env);
 798                        return rc;
 799                }
 800        }
 801
 802        hostinfo_clear(&hi);
 803        argv_array_clear(&env);
 804        logerror("Protocol error: '%s'", line);
 805        return -1;
 806}
 807
 808static int addrcmp(const struct sockaddr_storage *s1,
 809    const struct sockaddr_storage *s2)
 810{
 811        const struct sockaddr *sa1 = (const struct sockaddr*) s1;
 812        const struct sockaddr *sa2 = (const struct sockaddr*) s2;
 813
 814        if (sa1->sa_family != sa2->sa_family)
 815                return sa1->sa_family - sa2->sa_family;
 816        if (sa1->sa_family == AF_INET)
 817                return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
 818                    &((struct sockaddr_in *)s2)->sin_addr,
 819                    sizeof(struct in_addr));
 820#ifndef NO_IPV6
 821        if (sa1->sa_family == AF_INET6)
 822                return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
 823                    &((struct sockaddr_in6 *)s2)->sin6_addr,
 824                    sizeof(struct in6_addr));
 825#endif
 826        return 0;
 827}
 828
 829static int max_connections = 32;
 830
 831static unsigned int live_children;
 832
 833static struct child {
 834        struct child *next;
 835        struct child_process cld;
 836        struct sockaddr_storage address;
 837} *firstborn;
 838
 839static void add_child(struct child_process *cld, struct sockaddr *addr, socklen_t addrlen)
 840{
 841        struct child *newborn, **cradle;
 842
 843        newborn = xcalloc(1, sizeof(*newborn));
 844        live_children++;
 845        memcpy(&newborn->cld, cld, sizeof(*cld));
 846        memcpy(&newborn->address, addr, addrlen);
 847        for (cradle = &firstborn; *cradle; cradle = &(*cradle)->next)
 848                if (!addrcmp(&(*cradle)->address, &newborn->address))
 849                        break;
 850        newborn->next = *cradle;
 851        *cradle = newborn;
 852}
 853
 854/*
 855 * This gets called if the number of connections grows
 856 * past "max_connections".
 857 *
 858 * We kill the newest connection from a duplicate IP.
 859 */
 860static void kill_some_child(void)
 861{
 862        const struct child *blanket, *next;
 863
 864        if (!(blanket = firstborn))
 865                return;
 866
 867        for (; (next = blanket->next); blanket = next)
 868                if (!addrcmp(&blanket->address, &next->address)) {
 869                        kill(blanket->cld.pid, SIGTERM);
 870                        break;
 871                }
 872}
 873
 874static void check_dead_children(void)
 875{
 876        int status;
 877        pid_t pid;
 878
 879        struct child **cradle, *blanket;
 880        for (cradle = &firstborn; (blanket = *cradle);)
 881                if ((pid = waitpid(blanket->cld.pid, &status, WNOHANG)) > 1) {
 882                        const char *dead = "";
 883                        if (status)
 884                                dead = " (with error)";
 885                        loginfo("[%"PRIuMAX"] Disconnected%s", (uintmax_t)pid, dead);
 886
 887                        /* remove the child */
 888                        *cradle = blanket->next;
 889                        live_children--;
 890                        child_process_clear(&blanket->cld);
 891                        free(blanket);
 892                } else
 893                        cradle = &blanket->next;
 894}
 895
 896static struct argv_array cld_argv = ARGV_ARRAY_INIT;
 897static void handle(int incoming, struct sockaddr *addr, socklen_t addrlen)
 898{
 899        struct child_process cld = CHILD_PROCESS_INIT;
 900
 901        if (max_connections && live_children >= max_connections) {
 902                kill_some_child();
 903                sleep(1);  /* give it some time to die */
 904                check_dead_children();
 905                if (live_children >= max_connections) {
 906                        close(incoming);
 907                        logerror("Too many children, dropping connection");
 908                        return;
 909                }
 910        }
 911
 912        if (addr->sa_family == AF_INET) {
 913                char buf[128] = "";
 914                struct sockaddr_in *sin_addr = (void *) addr;
 915                inet_ntop(addr->sa_family, &sin_addr->sin_addr, buf, sizeof(buf));
 916                argv_array_pushf(&cld.env_array, "REMOTE_ADDR=%s", buf);
 917                argv_array_pushf(&cld.env_array, "REMOTE_PORT=%d",
 918                                 ntohs(sin_addr->sin_port));
 919#ifndef NO_IPV6
 920        } else if (addr->sa_family == AF_INET6) {
 921                char buf[128] = "";
 922                struct sockaddr_in6 *sin6_addr = (void *) addr;
 923                inet_ntop(AF_INET6, &sin6_addr->sin6_addr, buf, sizeof(buf));
 924                argv_array_pushf(&cld.env_array, "REMOTE_ADDR=[%s]", buf);
 925                argv_array_pushf(&cld.env_array, "REMOTE_PORT=%d",
 926                                 ntohs(sin6_addr->sin6_port));
 927#endif
 928        }
 929
 930        cld.argv = cld_argv.argv;
 931        cld.in = incoming;
 932        cld.out = dup(incoming);
 933
 934        if (start_command(&cld))
 935                logerror("unable to fork");
 936        else
 937                add_child(&cld, addr, addrlen);
 938}
 939
 940static void child_handler(int signo)
 941{
 942        /*
 943         * Otherwise empty handler because systemcalls will get interrupted
 944         * upon signal receipt
 945         * SysV needs the handler to be rearmed
 946         */
 947        signal(SIGCHLD, child_handler);
 948}
 949
 950static int set_reuse_addr(int sockfd)
 951{
 952        int on = 1;
 953
 954        if (!reuseaddr)
 955                return 0;
 956        return setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
 957                          &on, sizeof(on));
 958}
 959
 960struct socketlist {
 961        int *list;
 962        size_t nr;
 963        size_t alloc;
 964};
 965
 966static const char *ip2str(int family, struct sockaddr *sin, socklen_t len)
 967{
 968#ifdef NO_IPV6
 969        static char ip[INET_ADDRSTRLEN];
 970#else
 971        static char ip[INET6_ADDRSTRLEN];
 972#endif
 973
 974        switch (family) {
 975#ifndef NO_IPV6
 976        case AF_INET6:
 977                inet_ntop(family, &((struct sockaddr_in6*)sin)->sin6_addr, ip, len);
 978                break;
 979#endif
 980        case AF_INET:
 981                inet_ntop(family, &((struct sockaddr_in*)sin)->sin_addr, ip, len);
 982                break;
 983        default:
 984                xsnprintf(ip, sizeof(ip), "<unknown>");
 985        }
 986        return ip;
 987}
 988
 989#ifndef NO_IPV6
 990
 991static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
 992{
 993        int socknum = 0;
 994        char pbuf[NI_MAXSERV];
 995        struct addrinfo hints, *ai0, *ai;
 996        int gai;
 997        long flags;
 998
 999        xsnprintf(pbuf, sizeof(pbuf), "%d", listen_port);
1000        memset(&hints, 0, sizeof(hints));
1001        hints.ai_family = AF_UNSPEC;
1002        hints.ai_socktype = SOCK_STREAM;
1003        hints.ai_protocol = IPPROTO_TCP;
1004        hints.ai_flags = AI_PASSIVE;
1005
1006        gai = getaddrinfo(listen_addr, pbuf, &hints, &ai0);
1007        if (gai) {
1008                logerror("getaddrinfo() for %s failed: %s", listen_addr, gai_strerror(gai));
1009                return 0;
1010        }
1011
1012        for (ai = ai0; ai; ai = ai->ai_next) {
1013                int sockfd;
1014
1015                sockfd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1016                if (sockfd < 0)
1017                        continue;
1018                if (sockfd >= FD_SETSIZE) {
1019                        logerror("Socket descriptor too large");
1020                        close(sockfd);
1021                        continue;
1022                }
1023
1024#ifdef IPV6_V6ONLY
1025                if (ai->ai_family == AF_INET6) {
1026                        int on = 1;
1027                        setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
1028                                   &on, sizeof(on));
1029                        /* Note: error is not fatal */
1030                }
1031#endif
1032
1033                if (set_reuse_addr(sockfd)) {
1034                        logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1035                        close(sockfd);
1036                        continue;
1037                }
1038
1039                set_keep_alive(sockfd);
1040
1041                if (bind(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) {
1042                        logerror("Could not bind to %s: %s",
1043                                 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1044                                 strerror(errno));
1045                        close(sockfd);
1046                        continue;       /* not fatal */
1047                }
1048                if (listen(sockfd, 5) < 0) {
1049                        logerror("Could not listen to %s: %s",
1050                                 ip2str(ai->ai_family, ai->ai_addr, ai->ai_addrlen),
1051                                 strerror(errno));
1052                        close(sockfd);
1053                        continue;       /* not fatal */
1054                }
1055
1056                flags = fcntl(sockfd, F_GETFD, 0);
1057                if (flags >= 0)
1058                        fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1059
1060                ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1061                socklist->list[socklist->nr++] = sockfd;
1062                socknum++;
1063        }
1064
1065        freeaddrinfo(ai0);
1066
1067        return socknum;
1068}
1069
1070#else /* NO_IPV6 */
1071
1072static int setup_named_sock(char *listen_addr, int listen_port, struct socketlist *socklist)
1073{
1074        struct sockaddr_in sin;
1075        int sockfd;
1076        long flags;
1077
1078        memset(&sin, 0, sizeof sin);
1079        sin.sin_family = AF_INET;
1080        sin.sin_port = htons(listen_port);
1081
1082        if (listen_addr) {
1083                /* Well, host better be an IP address here. */
1084                if (inet_pton(AF_INET, listen_addr, &sin.sin_addr.s_addr) <= 0)
1085                        return 0;
1086        } else {
1087                sin.sin_addr.s_addr = htonl(INADDR_ANY);
1088        }
1089
1090        sockfd = socket(AF_INET, SOCK_STREAM, 0);
1091        if (sockfd < 0)
1092                return 0;
1093
1094        if (set_reuse_addr(sockfd)) {
1095                logerror("Could not set SO_REUSEADDR: %s", strerror(errno));
1096                close(sockfd);
1097                return 0;
1098        }
1099
1100        set_keep_alive(sockfd);
1101
1102        if ( bind(sockfd, (struct sockaddr *)&sin, sizeof sin) < 0 ) {
1103                logerror("Could not bind to %s: %s",
1104                         ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1105                         strerror(errno));
1106                close(sockfd);
1107                return 0;
1108        }
1109
1110        if (listen(sockfd, 5) < 0) {
1111                logerror("Could not listen to %s: %s",
1112                         ip2str(AF_INET, (struct sockaddr *)&sin, sizeof(sin)),
1113                         strerror(errno));
1114                close(sockfd);
1115                return 0;
1116        }
1117
1118        flags = fcntl(sockfd, F_GETFD, 0);
1119        if (flags >= 0)
1120                fcntl(sockfd, F_SETFD, flags | FD_CLOEXEC);
1121
1122        ALLOC_GROW(socklist->list, socklist->nr + 1, socklist->alloc);
1123        socklist->list[socklist->nr++] = sockfd;
1124        return 1;
1125}
1126
1127#endif
1128
1129static void socksetup(struct string_list *listen_addr, int listen_port, struct socketlist *socklist)
1130{
1131        if (!listen_addr->nr)
1132                setup_named_sock(NULL, listen_port, socklist);
1133        else {
1134                int i, socknum;
1135                for (i = 0; i < listen_addr->nr; i++) {
1136                        socknum = setup_named_sock(listen_addr->items[i].string,
1137                                                   listen_port, socklist);
1138
1139                        if (socknum == 0)
1140                                logerror("unable to allocate any listen sockets for host %s on port %u",
1141                                         listen_addr->items[i].string, listen_port);
1142                }
1143        }
1144}
1145
1146static int service_loop(struct socketlist *socklist)
1147{
1148        struct pollfd *pfd;
1149        int i;
1150
1151        pfd = xcalloc(socklist->nr, sizeof(struct pollfd));
1152
1153        for (i = 0; i < socklist->nr; i++) {
1154                pfd[i].fd = socklist->list[i];
1155                pfd[i].events = POLLIN;
1156        }
1157
1158        signal(SIGCHLD, child_handler);
1159
1160        for (;;) {
1161                int i;
1162
1163                check_dead_children();
1164
1165                if (poll(pfd, socklist->nr, -1) < 0) {
1166                        if (errno != EINTR) {
1167                                logerror("Poll failed, resuming: %s",
1168                                      strerror(errno));
1169                                sleep(1);
1170                        }
1171                        continue;
1172                }
1173
1174                for (i = 0; i < socklist->nr; i++) {
1175                        if (pfd[i].revents & POLLIN) {
1176                                union {
1177                                        struct sockaddr sa;
1178                                        struct sockaddr_in sai;
1179#ifndef NO_IPV6
1180                                        struct sockaddr_in6 sai6;
1181#endif
1182                                } ss;
1183                                socklen_t sslen = sizeof(ss);
1184                                int incoming = accept(pfd[i].fd, &ss.sa, &sslen);
1185                                if (incoming < 0) {
1186                                        switch (errno) {
1187                                        case EAGAIN:
1188                                        case EINTR:
1189                                        case ECONNABORTED:
1190                                                continue;
1191                                        default:
1192                                                die_errno("accept returned");
1193                                        }
1194                                }
1195                                handle(incoming, &ss.sa, sslen);
1196                        }
1197                }
1198        }
1199}
1200
1201#ifdef NO_POSIX_GOODIES
1202
1203struct credentials;
1204
1205static void drop_privileges(struct credentials *cred)
1206{
1207        /* nothing */
1208}
1209
1210static struct credentials *prepare_credentials(const char *user_name,
1211    const char *group_name)
1212{
1213        die("--user not supported on this platform");
1214}
1215
1216#else
1217
1218struct credentials {
1219        struct passwd *pass;
1220        gid_t gid;
1221};
1222
1223static void drop_privileges(struct credentials *cred)
1224{
1225        if (cred && (initgroups(cred->pass->pw_name, cred->gid) ||
1226            setgid (cred->gid) || setuid(cred->pass->pw_uid)))
1227                die("cannot drop privileges");
1228}
1229
1230static struct credentials *prepare_credentials(const char *user_name,
1231    const char *group_name)
1232{
1233        static struct credentials c;
1234
1235        c.pass = getpwnam(user_name);
1236        if (!c.pass)
1237                die("user not found - %s", user_name);
1238
1239        if (!group_name)
1240                c.gid = c.pass->pw_gid;
1241        else {
1242                struct group *group = getgrnam(group_name);
1243                if (!group)
1244                        die("group not found - %s", group_name);
1245
1246                c.gid = group->gr_gid;
1247        }
1248
1249        return &c;
1250}
1251#endif
1252
1253static int serve(struct string_list *listen_addr, int listen_port,
1254    struct credentials *cred)
1255{
1256        struct socketlist socklist = { NULL, 0, 0 };
1257
1258        socksetup(listen_addr, listen_port, &socklist);
1259        if (socklist.nr == 0)
1260                die("unable to allocate any listen sockets on port %u",
1261                    listen_port);
1262
1263        drop_privileges(cred);
1264
1265        loginfo("Ready to rumble");
1266
1267        return service_loop(&socklist);
1268}
1269
1270int cmd_main(int argc, const char **argv)
1271{
1272        int listen_port = 0;
1273        struct string_list listen_addr = STRING_LIST_INIT_NODUP;
1274        int serve_mode = 0, inetd_mode = 0;
1275        const char *pid_file = NULL, *user_name = NULL, *group_name = NULL;
1276        int detach = 0;
1277        struct credentials *cred = NULL;
1278        int i;
1279
1280        for (i = 1; i < argc; i++) {
1281                const char *arg = argv[i];
1282                const char *v;
1283
1284                if (skip_prefix(arg, "--listen=", &v)) {
1285                        string_list_append(&listen_addr, xstrdup_tolower(v));
1286                        continue;
1287                }
1288                if (skip_prefix(arg, "--port=", &v)) {
1289                        char *end;
1290                        unsigned long n;
1291                        n = strtoul(v, &end, 0);
1292                        if (*v && !*end) {
1293                                listen_port = n;
1294                                continue;
1295                        }
1296                }
1297                if (!strcmp(arg, "--serve")) {
1298                        serve_mode = 1;
1299                        continue;
1300                }
1301                if (!strcmp(arg, "--inetd")) {
1302                        inetd_mode = 1;
1303                        continue;
1304                }
1305                if (!strcmp(arg, "--verbose")) {
1306                        verbose = 1;
1307                        continue;
1308                }
1309                if (!strcmp(arg, "--syslog")) {
1310                        log_destination = LOG_DESTINATION_SYSLOG;
1311                        continue;
1312                }
1313                if (skip_prefix(arg, "--log-destination=", &v)) {
1314                        if (!strcmp(v, "syslog")) {
1315                                log_destination = LOG_DESTINATION_SYSLOG;
1316                                continue;
1317                        } else if (!strcmp(v, "stderr")) {
1318                                log_destination = LOG_DESTINATION_STDERR;
1319                                continue;
1320                        } else if (!strcmp(v, "none")) {
1321                                log_destination = LOG_DESTINATION_NONE;
1322                                continue;
1323                        } else
1324                                die("unknown log destination '%s'", v);
1325                }
1326                if (!strcmp(arg, "--export-all")) {
1327                        export_all_trees = 1;
1328                        continue;
1329                }
1330                if (skip_prefix(arg, "--access-hook=", &v)) {
1331                        access_hook = v;
1332                        continue;
1333                }
1334                if (skip_prefix(arg, "--timeout=", &v)) {
1335                        timeout = atoi(v);
1336                        continue;
1337                }
1338                if (skip_prefix(arg, "--init-timeout=", &v)) {
1339                        init_timeout = atoi(v);
1340                        continue;
1341                }
1342                if (skip_prefix(arg, "--max-connections=", &v)) {
1343                        max_connections = atoi(v);
1344                        if (max_connections < 0)
1345                                max_connections = 0;            /* unlimited */
1346                        continue;
1347                }
1348                if (!strcmp(arg, "--strict-paths")) {
1349                        strict_paths = 1;
1350                        continue;
1351                }
1352                if (skip_prefix(arg, "--base-path=", &v)) {
1353                        base_path = v;
1354                        continue;
1355                }
1356                if (!strcmp(arg, "--base-path-relaxed")) {
1357                        base_path_relaxed = 1;
1358                        continue;
1359                }
1360                if (skip_prefix(arg, "--interpolated-path=", &v)) {
1361                        interpolated_path = v;
1362                        continue;
1363                }
1364                if (!strcmp(arg, "--reuseaddr")) {
1365                        reuseaddr = 1;
1366                        continue;
1367                }
1368                if (!strcmp(arg, "--user-path")) {
1369                        user_path = "";
1370                        continue;
1371                }
1372                if (skip_prefix(arg, "--user-path=", &v)) {
1373                        user_path = v;
1374                        continue;
1375                }
1376                if (skip_prefix(arg, "--pid-file=", &v)) {
1377                        pid_file = v;
1378                        continue;
1379                }
1380                if (!strcmp(arg, "--detach")) {
1381                        detach = 1;
1382                        continue;
1383                }
1384                if (skip_prefix(arg, "--user=", &v)) {
1385                        user_name = v;
1386                        continue;
1387                }
1388                if (skip_prefix(arg, "--group=", &v)) {
1389                        group_name = v;
1390                        continue;
1391                }
1392                if (skip_prefix(arg, "--enable=", &v)) {
1393                        enable_service(v, 1);
1394                        continue;
1395                }
1396                if (skip_prefix(arg, "--disable=", &v)) {
1397                        enable_service(v, 0);
1398                        continue;
1399                }
1400                if (skip_prefix(arg, "--allow-override=", &v)) {
1401                        make_service_overridable(v, 1);
1402                        continue;
1403                }
1404                if (skip_prefix(arg, "--forbid-override=", &v)) {
1405                        make_service_overridable(v, 0);
1406                        continue;
1407                }
1408                if (!strcmp(arg, "--informative-errors")) {
1409                        informative_errors = 1;
1410                        continue;
1411                }
1412                if (!strcmp(arg, "--no-informative-errors")) {
1413                        informative_errors = 0;
1414                        continue;
1415                }
1416                if (!strcmp(arg, "--")) {
1417                        ok_paths = &argv[i+1];
1418                        break;
1419                } else if (arg[0] != '-') {
1420                        ok_paths = &argv[i];
1421                        break;
1422                }
1423
1424                usage(daemon_usage);
1425        }
1426
1427        if (log_destination == LOG_DESTINATION_UNSET) {
1428                if (inetd_mode || detach)
1429                        log_destination = LOG_DESTINATION_SYSLOG;
1430                else
1431                        log_destination = LOG_DESTINATION_STDERR;
1432        }
1433
1434        if (log_destination == LOG_DESTINATION_SYSLOG) {
1435                openlog("git-daemon", LOG_PID, LOG_DAEMON);
1436                set_die_routine(daemon_die);
1437        } else
1438                /* avoid splitting a message in the middle */
1439                setvbuf(stderr, NULL, _IOFBF, 4096);
1440
1441        if (inetd_mode && (detach || group_name || user_name))
1442                die("--detach, --user and --group are incompatible with --inetd");
1443
1444        if (inetd_mode && (listen_port || (listen_addr.nr > 0)))
1445                die("--listen= and --port= are incompatible with --inetd");
1446        else if (listen_port == 0)
1447                listen_port = DEFAULT_GIT_PORT;
1448
1449        if (group_name && !user_name)
1450                die("--group supplied without --user");
1451
1452        if (user_name)
1453                cred = prepare_credentials(user_name, group_name);
1454
1455        if (strict_paths && (!ok_paths || !*ok_paths))
1456                die("option --strict-paths requires a whitelist");
1457
1458        if (base_path && !is_directory(base_path))
1459                die("base-path '%s' does not exist or is not a directory",
1460                    base_path);
1461
1462        if (log_destination != LOG_DESTINATION_STDERR) {
1463                if (!freopen("/dev/null", "w", stderr))
1464                        die_errno("failed to redirect stderr to /dev/null");
1465        }
1466
1467        if (inetd_mode || serve_mode)
1468                return execute();
1469
1470        if (detach) {
1471                if (daemonize())
1472                        die("--detach not supported on this platform");
1473        }
1474
1475        if (pid_file)
1476                write_file(pid_file, "%"PRIuMAX, (uintmax_t) getpid());
1477
1478        /* prepare argv for serving-processes */
1479        argv_array_push(&cld_argv, argv[0]); /* git-daemon */
1480        argv_array_push(&cld_argv, "--serve");
1481        for (i = 1; i < argc; ++i)
1482                argv_array_push(&cld_argv, argv[i]);
1483
1484        return serve(&listen_addr, listen_port, cred);
1485}